Posted
by
CmdrTaco
on Monday November 08, 2010 @12:33PM
from the i-do-that-when-i-eat-chinese dept.

buildslave writes "The Large Hadron Collider has successfully created a 'mini-Big Bang' by smashing together lead ions instead of protons. The scientists working at the enormous machine on the Franco-Swiss border achieved the unique conditions on 7 November. The experiment created temperatures a million times hotter than the center of the Sun."

Yup, it does, but we can do fusion. If we just cared about fusing atoms together, that was doable by ZETA (primitive tokamak) in the 1950's. But making a reactor that can generate net energy gain is a trick.

We don't have any trouble creating the necessary temperature for controlled fusion. The part we aren't able to do is the "controlled" bit - in a way that allows a net positive energy return.

I'm guessing this collision released maybe a few kcal of energy (which is HUGE for two atom-sized masses, but otherwise on-par with a candle), but it probably consumed the resources from half of a power plant in the process.

The LHC isn't about energy generation - it is about generating huge concentrations of energy in an extremely small volume of space.

[blockquote]The 'big bang [wikipedia.org]' was the event that created all mass, space, and time in the entire universe in a single instant approximately 13.7 billion years ago.[/blockquote]

The big bang doesn't talk about the creation event. It discusses the expansion following soon after that event, and only somewhat reliably at the planck epoch. The big bang did not create matter, energy or time either. These were all firmly in place by during the period this theory takes place. While their may be theories floating around about the actual creation event, none are more than idle speculation.

The big bang doesn't talk about the creation event. It discusses the expansion following soon after that event...

The 'big bang' theory is that the universe began as the appearance of a 'singularity' approximately 13.7 billion years ago that then rapidly expanded into the universe that we see today. According to the theory, neither 'mass' nor 'space' nor 'time' existed prior to the singularity.

Steven W. Hawking, Roger Penrose, "The Singularities of Gravitational Collapse and Cosmology," Proceedings of the Royal Society of London, series A, 314 (1970) pp. 529-548.

I'd imagine a mass the size of two lead ions at a trillion degrees could only maybe bring a gallon of room temperature water up a degree or two. They are quite small.

Just to keep things in context, they actually shot a rather large number of lead ions at each other in the hopes of getting two to collide.There's a huge amount of energy zipping around, it's just that the odds of it all releasing at once approaches zero.

The LHC collision of lead ions did not create any mass,
space, or time but did create a "hot dense soup of quarks and gluons
known as a quark-gluon plasma" that might have existed after the 'big
bang' event.

You can be damn sure it did create a whole lot of mass. When you reach even a tiny fraction of the energy involved here you start creating exotic particles left right and centre. The quarks in the soup will not be limited to up and down quarks found in lead ions, much heavier quarks will have been created though they can be very short lived.

It's actually 0.1mJ (or 1138TeV) per collision (half that per ion). They have ways to go before hitting 1 cal. However, within the volume of a nucleus, that's still a crazy concentration of energy.

Also, a beam has a *lot* of ions (they're starting with 2e10/beam but I believe their goal is 100x that before the end of the month). That's 10MJ/beam before the end of the month, which is already a fairly serious amount of energy to have in a particle beam.

It's between particles, regardless of their kind. At room temperature, atoms within molecules also participate in heat exchange; this is why for adiabatic compression of ideal gas you need to know if it has monoatomic, biatomic or bigger molecules - this affects the vibrational modes within the molecule. Again at room temperature, quantum physics prevents this exchange to continue inside the atoms - in non-metals, the atom-atom collisions happen below the energy that can knock electrons out of them, let alone affect their nuclei.

But here we're talking about many orders of magnitude above room temperature, and what used to happens to molecules and atoms inside them happens to quarks and gluons. The important thing is that in proton collisions, the particles don't stay together long enough to achieve thermal equilibrium, so it makes no sense to talk about thermodynamics. But with lead ions, if quark-gluon plasma formation in fact happens (gathering data needed to prove or disprove this is part of the experiment), the particles interact enough times that we can talk about temperatures, pressures and so on.

Eh, actually it's pretty much nothing like that. Unless you're kookie enough to think that the amount of energy involved in the Big Bang was infinite. If it was a finite amount, then talking about something being a fraction of that is a perfectly reasonable thing to do, and the answer is far, far short of infinity, no matter how big it is.